Dray cell.



E. C. SMITH.

DRY CELL.

APPLICATION FILED 'OCT- IB, i912.

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NVENTOR EDWARD C. SMITH @y/bww ATTORNEY WITNESSES nar crm.

Specification of Letters Patent.

Patented am. at, mia.

- VApplication lezl` October 18, 1912. Serial No. 726,419.`

To all fwwm, it may concern: Y

Be it known that I, EDWARD C. S, a citizen of the United States, and aresident of Toronto, in the county of York, ntario, lCanada, haveinvented new and useful Improvements in DryCells, of which the followingis a clear andexact description.

This invention relates to dry cells and the object is to securely holdthe compressed mix in place in the cell so that theinternal resistancemay not be increased by the looseningof the mix.

In the process of manufacture of dry cells the battery mix is tamped inthe containers around the carbon electrodes by machine orby hand, andthe cells are usually carted to various places in the factory to haveadditional work performed on`them before the nal asphaltum or other sealis added. In V this process of handling, the mix is liable to be `jarredloose and cause an increase in the internal resistance. In shipping orin the use of the cells after the usual seal is4 applied the mix isliable to bejarred loose and cause theV same trouble.

The purpose of my invention is to obviate to a greater extent thesediculties. The manner in which this is accomplished is given in theappended description, reference also being had to the drawings in which;

Figure 1 is a sectional view of a cell with my invention applied. `Fig.2 is a plan view of the clamping disk used to retain thelmix in place.Fig. 3 is a section. taken on the line A-A of Fig. 2. Fig. 4 is amodified form of the invention.

Referring to Fig. 1, l represents the carbon electrode in an ordinarydry cell. 2 is the battery mix compacted about the electrode 1. `3 isthe pitch seal, 4 is the container which is also the positive electrodeand 4 is the lining of the cell. 5 is the device which embodies myinvention. It consists of a disk of pulpboard or other suitablematerial, of circular or any other suitable its edge or. by that part ofits lower surface which may be upturned against the side of thecontainer as shown at 7. The disk 5 may have a slot or notch 8 cut atthe edge to perm-1t -the escape ofl gas from the cell.

. In Fig. 4 a slightly different arrangement 1s shown to accomplish thesame result. In

this case the disk 5 has a central hole that tightly .fits theelectrode. Preferably the lhole should be small enough for part of thedisk to be upturned as shown'in this figure. If desired the disk may bemade so that it canbind both on the container and on the electrode.However, since the electrode is not always exactly in the center it willbe found best to have the disk bind only on one of the parts.

In prior construction of dry cells, sand or sawdust has been putupon thetops of dry cells, and the seal poured upon them. This vconstructionleaves a region of loose yielding material above the mix and linin andbelow the seal. Any blow or jar whic the cell so constructed may receivewill tend to loosen the mix about the electrode, because the mass of themix can yield and compress the loose material above it. In yielding tosuch blows and jars, the bond between the mix and electrode isbroken toa greater or less extent, which increases Vthe internal resistance,consequently lowering the initial amperage of the cell. Such damageoften occurs to cells by rough handling either during manufacture or intransit or in use as previously explained. In order'to prevent thisdamage of loosenin the battery mix and consequent loss in e ciency, Ihave invented the disk described above. -By driving said disk down uponthe compacted mix a surface binding a ainst the container is introducedAwhich .will resist the tendency of the mix to be driven upward aby jars,and prevent the loosening of the mix fromv the electrode and consequentloss of efficiency of the cell;`

The disk which embodies my invention may be made of paper, pulpboard,ber, or any other suitable material which is a nonconductor ofelectricity, and which has sum# cient rigidity to hold its shape whileit binds against the side of the Icontainer with its edge, and sucientelasticity to permit itsbending without breaking at the edge if the diskis made so large that the edge is upturned against the container.Urdinary Mt pulpboard is absorbent and will become Wet 1 and lose itsrigidity if used for the retaining disk.- The disk if made of absorbentmaterial should therefore be coated or treated with pitch, paraiiin,paint or other material to prevent it becoming moist. The preferredmethod is to apply a coating of pitch paint 9 to the disk and also theupper part ofthe electrode and container. Then when the pitch seal ispoured on top it will adhere to the disk, container and electrode toform a very rigid seal. z It is not-new to use a paper lining under thepitch seal, but all such liningsare absorbent and furthermore fitloosely in the cell. So far as I know I am the first to use anon-absorbent disk tightly compressed in the cell to aid'the pitch sealin retaining the mix in place. With the seal applied directly upon thisdisk the mix in the cell is locked in place with no space occupied byyielding material to permit loosening.

Having described my invention, what I claim is:-

1. In a dry cell,v a container electrode, a

mix compressed therein, a second electrode in the mix, and a rigid diskhaving a hole therethrough and having an edge upturned against one ofsaid electrodes to retain the mixvin place.

2. In a dry cell, a container electrode, a mix compressed therein, asecond electrode in the mix, a rigid disk bindin tightly against saidelectrodes and packed -against the top of the `mix and a pitch seal ontop of said disk. c

3. In a dry cell, a container electrode, a linin Within the containerhaving a mix thereln, and having the upper portion of the lining foldedover the mix, a second eleotrode in the mix and a rigid disk bindingtightly against one of said electrodes to retam the mix and foldedportion of the lining. y

In testimony whereof I have hereunto signed my name.

EDWARD C. SMITH. In the presence of- D. S. TovELL,

A. E. COOPER.

